The present invention is an improvement of a process roll used for processing uniformly flat products such as polymer sheet. More specifically, the invention is a deflection dampening apparatus which enables the adjustment of the process roll while mounted.
Process rolls of many types and sizes are used for processing a variety of flat materials, such as steel plate, paper, fabric, plastics and rubber. Typically, the material is passed through a series of stacked, temperature controlled rolls that serve to flatten the material into a continuous sheet or web having a desired thickness.
One problem with processing flat materials is the inevitable deflection in the rolls caused by xe2x80x9cseparatingxe2x80x9d forces created by the materials"" resistance to deformation as its thickness is decreased. Several attempts have been made in the past to reduce roll deflection and thereby increase uniformity in the material being processed, as described in U.S. Pat. No. 242,058 to Schurmann, U.S. Pat. No. 4,158,128 to Evdokimov, U.S. Pat. No. 4,823,450 to Ramisch, and U.S. Pat. No. 5,567,488 to Frankland. A problem with these rolls, however, is the inability to quickly and easily alter the roll parameters mechanically while the roll is secured in the roll stand, in order to maintain or increase uniformity of thickness of the processed material as the roll wears.
More specifically, and as an example, U.S. Pat. No. 5,567,448 provides a flat sheet extrusion system using rolls with cantilever contact members. As the rolls are used repeatedly the modulus of elasticity of the cantilever contact member starts to diminish and the amount of deflection increases. As a result, the thickness of the outer edges becomes greater and the quality of the finished product decreases, thereby raising the cost of manufacturing the finished goods. Ultimately, time consuming adjustment and inevitably replacement of the roll is required.
There is a need for an apparatus, therefore, that will enable easy, quick, and cost effective modification to the roll parameters to more finely adjust the thickness of the finished rolled material as dynamics change with time.
The present invention is directed to a dampening ring or apparatus that is used to adjust the deflection of the contact surface of a cantilever contact member, such as the inner shell member of the roll described in the U.S. Pat. No. 5,567,448 to Frankland.
In the instant invention, the deflection dampening apparatus comprises a pair of interlocking semicircular or C-shaped portions that form a ring, each portion having an inner base and a notched outer surface. The notched outer surface has a pair of finned side walls. A plurality of screws are attached through openings in the notched outer surface and threaded openings in the inner base. The screws communicate with the finned side walls, whereby tightening the screw causes a continuous xe2x80x9cCxe2x80x9d shaped wedging washer to force the fins to extend radially outwardly and wedge between the cantilevered contact member and the cylindrical core or axle of the process roll. When securely wedged therebetween, the dampening apparatus decreases the deflection of the cantilevered contact member of the process roll. Since each roll typically has a cantilevered contact member on both sides of the cylindrical core, a second dampening ring is mounted on the opposite side to match the deflection effect thereof.
The two part interlocking dampening ring provides a user with a quick and easy way of adjusting the deflection of the cantilevered contact member without removing the roll from the roll stand, as the pair of C-shaped portions are opened in a clam-like fashion, slipped around the cylindrical core of the roll and positioned into the void formed between the cantilevered contact member and the cylindrical core, interlocked and manually tightened to wedge therebetween. Multiple dampening rings may be used and/or the dampening ring may be manually positioned at a particular location along said void to adjust the pivot point of the cantilevered contact member until the optimum amount of deflection is achieved.
Those skilled in the art can appreciate that the dampening ring apparatus may be economically made from a variety of known materials. Many other objects and features of the present invention will be obvious to those of skill in the art upon contemplation of the disclosure herein in connection with the accompanying drawings.